Electrical resistance element



Nov. 25, 1941- V as. DEAN 2,263,571

ELECTRICAL RESISTANCE ELEMENT Filed April 13, 1939 OHMS jab 8o 'SPECIFKT ELEc'rRcAL RESISTANCE TE MPERATURE COEFFICIENT maa arzeae ROCKWELL c.

abletooom lilemhish -a v'eryiow Patented Nov. 25, 1941 lJNiTED STATES PATENT: orrlcs Q snsc'ralcsr. Sa s Zines ELEM l I Beginal s. Dean,- w E;

Chioago'Developmmny, Chicago 111.,

asaignor to v a corporation r, Illinois Appheation "April 13, isss serial No. 287,707

'iClaims.

. trical resistance, with mechanical properties such as high strength and modulus of elasticity.

In my copending application, Serial No. 230,209,

tiled September 16, v1938, I have disclosed that certain copper-manganese alloys possess great electrical resistance and lowtemperature coemcients. The present invention relatesto methods of obtaining any desired combination oivaiious mechanical and electrical properties by a selection of composition, heat and mechanical treatment 0! manganese-copper'alloys. As set forth in my copending application, the electrical prop.-'

erties oi copper-manganese alloys made from electrolytic manganese or substantially pure manganese diiier greatly from those of the prior art which are made from commercial manganese containing silicon, aluminum and thelike. I have found that, by the use or electrolytic manganese or other manganese or like purity, alloys diagram that. by the practice of my invention, 1 produce quenched and cold-worked alloys of approximately equal of copper and manganese having specific resistances of more than .MxliH ohms/cm). For purposes at comparison. it may be pointed out that the highest'rehave heretoiore recorded in the work of other investigators which has come to our attention is' 134x11? ohms/cm This increase in resistance. which is oigreat .im-

portaneeinelech-icalcircuitaisobtainedbytbe meoihishpm'itymansaneeeand bythequenohlnltreahnentwhichlhavedescrlbed. 'Ihetemperature ooeiiicient or electrical resistance or the alloya'ma'de in accordance with my invention andquenched or cold worked is fl roughoutthecompositionrangetrom fltoloi The advantages oi being resistance-with ture ooeillcient as br'theapplicationoi myinventionwlil K 'ject the alloys of my invention to heat treatment 0 a. are produced which are ductile throughout the to those accustomed to working with electrical circuits.

For certain purposes. it is desirable to obtain increased hardness in electrical resistance alloys. This may be accomplished by cold work, by which means the hardness of alloys throughout the range may be considerably increased without greatly aflecting their electrical resistance or temperature coemcient. However, when it is desirable to obtain a maximum of hardness, I subat approximately 500 degrees C. for one-halt hour after quenching from 1000 degrees and cold working.

In Fig. 2 I have plotted the hardness of the copper-manganese alloys which can be obtained by the various treatments which I have described. It will be seen um; with high manganese alloys, it is possible to obtain hardness of more than. Rockwell (2-40 combined with an electrical resistance of greater than 100 10 ohms/cm).

What I claim as new and desire to protect by Letters Patent 01 the United States is: a

1. An electrical resistance element,-having a specific resistance oi at least about 150 10* ohms per cm), said element being made from an alloy selected from the group consisting oi quenched'and quenched 'and cold worked alloys consisting substantially entirely or manganese and copper. .said alloys containing from about 22% to about manganese. 2. An' electrical resistance element havinga hardness of atleast Rockwell 0-20 and an electrical resistance of at least x10 ohms/cm).

sesaid elementbeing made from an alloyconsisting tnnslectrlcalreaistance neiebeing entirely of and copper. said alloy containing-from about 00% to about 01% manganese.

a. An electrical element in more- ."ancewith'claim l the manganese-is electrolytlomanganese.

.Aneiectrlcalresistanc'eelementin accordance withclaim 2 wherein the manganese is I elementmadeirom an alloyselecied from the group consisting oi quenchedandquenchedandcoldworkedcoppermanganuealloyshavlngaspeciflcresistancein excess 0! x10 per an), the mug. praaentinhtomrtimsrlnflmhom abontflfitoabout'liflthebalancebeingmb- 0.Aresistaneaelementcomprlsing aeopperispoaaible manganesea'llcyh avingbetween aboutloitand 00$ copper,

quenched fron'i a high temperature but below the in: point and consisting substantially entirely'oi" melting point of the alloy, and having a specific copper and manganese. said alloy having a spe-.

electrical resistance. not substantially less than cific resistance of at least 150X10- ohms per about 150x 1H ohms/cm v cm said alloy containing between 40% and 50% 7. An electrical resistance element, said ele- 5 manganese, balance copper.

ment being made Irom an alloy quenched from a relatively high temperature but below its melt- REGINALD S. DEAN. 

